You're being unfair to the poor guy. It's not as if those quotations are without context and basis. It's also not as if he doesn't have a whole raft of other recorded quotations which provide evidence for his humility. Consider, for example,

> A hundred times every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving...

The dice quote makes more sense when you consider Einstein's personal philosophy, which had led him to discover relativity and aspects of QM. He strongly believed that once you uncover nature's secrets, not only do you understand the universe more, but you see why nothing else could possibly have been the case. Quantum mechanics as it was formulated/interpreted in his time violated this principle, thus he was motivated to look for the deeper secret. We're still arguing whether there's something deeper to this day. The particular type of model Einstein was exploring may have been dismissed, but you cannot fault his motivation - all physicists need one.